The invention relates to a method and apparatus for damping vibrations in large structures, such as buildings, bridges, and the like. The damping shall be effective throughout a wide range of vibration-causing frequencies beginning with the noise caused by people walking on concrete floors and reaching all the way to vibrations that may be caused by earthquakes. Vibrations caused by traffic adjacent a building or by overhead aircraft flights shall also be effectively damped by the present invention.
It is known to use so-called secondary damping means for damping vibrations of equipment such as machines in a factory. However, the possibilities of using secondary damping means are unknown in the construction of buildings except for the use of so-called plastic hinges in the steel reinforcement of buildings whereby the surrounding concrete is deformed in a plastic manner. The damping caused by such plastic deformation is taken into account when calculating the dimensions of earthquake proof buildings. However, the damping becomes effective only at relatively large loads. Additionally, the resulting deformations are not reversible. Vibrations below this large load limit are damped only by the relatively small inherent or self-damping of the construction materials. Therefore, there is room for improvement in the art of damping large structures against vibrations in a wide range of frequencies.